The present invention relates an improvement of a buckle, which is formed of a female buckle in a hollow shape, and a male buckle engaging the female buckle through an insertion section of the female buckle, to thereby connect a member or an article attached to the male buckle and a member or an article attached to the female buckle by engaging the male buckle with the female buckle.
Conventionally, there has been known a buckle, which is formed of a male buckle including an insertion section formed of a middle leg and elastic legs provided at both sides of the middle leg; and a female buckle in a hollow shape, which receives the insertion section of the male buckle while the elastic legs thereof are inwardly bent. The female buckle includes engaging windows which receive engaging projections provided at the elastic legs by the elastic return of the elastic legs at predetermined insertion positions, so that the engaging windows are engaged with the engaging projections.
In the buckle, the male buckle and the female buckle are connected by the engagements of the engaging projections of the elastic legs of the male buckle with the engaging windows of the female buckle, and by connecting the male and female buckles, a connection of bands, belts, straps or the like is carried out. Also, when the engaging projections are pressed through the engaging windows so that the elastic legs are inwardly bent again, the engagements between the engaging projections and the engaging windows are released, and the insertion section of the male buckle can be pulled out from the female buckle. Accordingly, connection of the belts or the like can be released by the separation of the male buckle from the female buckle.
However, in this kind of buckle, since the female buckle is formed of a simple hollow shape including the engaging windows, in the separated condition of the buckles in which the insertion section of the male buckle is not inserted in the female buckle, in case a force for smashing the female buckle is applied to the female buckle, there is a limit in improving the strength of the female buckle.
Accordingly, a main object of the invention is to improve a strength of a female buckle in this kind of the buckle without deteriorating the function of the buckle and without making the structure thereof complicated.
Further objects and advantages of the invention will be apparent from the following description of the invention.
To achieve the aforementioned object, the present invention provides a buckle which has the following structures (1) through (4) according to a first aspect of the invention.
(1) The buckle is formed of a female buckle having a hollow shape and including an introduction opening at at least one end thereof, and a male buckle including an insertion section to be inserted into the female buckle through the introduction opening thereof.
(2) The insertion section of the male buckle includes a middle leg, and elastic legs provided at both sides of the middle leg, and engaging projections are formed in the elastic legs at the sides opposite to sides facing the middle leg.
(3) The female buckle includes engaging windows engaging the engaging projections in the elastic legs. The elastic legs are elastically deformed inwardly by pressing the engaging projections against inner walls of one pair among two pairs of inner walls of the female buckle facing each other upon an insertion operation of the insertion section, and the engaging windows allow the elastic projections to enter thereinto by the elastic forces of the elastic legs at predetermined insertion positions.
(4) The female buckle also includes a pair of dividing plate portions, which guide the middle leg by holding the same therebetween in case of the insertion operation, and the dividing plate portions extend between the other pair of the inner walls of the female buckle among the two pairs facing each other.
According to this structure, by utilizing the pair of the dividing plate portions which guide an insertion of the insertion section of the male buckle by holding the middle leg of the male buckle therebetween, an inside of the female buckle in the hollow form can be supported, so that the strength of the female buckle can be improved without deteriorating the function of the buckle.
According to a second aspect of the invention, the insertion section of the male buckle according to the first aspect of the invention includes stopping portions between the middle leg and the elastic legs, and each of the stopping portions has a thickness to be held substantially tightly between the inner walls between which the dividing plate portions extend.
According to the above structure, in the engaging condition of the female and male buckles, in which the insertion section of the male buckle is inserted into the female buckle, the insertion section can be retained inside the female buckle without wobbling. In this situation, even if an external force in the direction of twisting the insertion section, which acts around a central axis of the female buckle, is applied, the engaging condition of the buckles can be maintained stably.
Also, according to a third aspect of the invention, the insertion section of the male buckle according to the first aspect of the invention includes stopping portions between the middle leg and the elastic legs. The stopping portions are provided for preventing bending of the elastic legs by abutting against the sides of the elastic legs facing the middle leg in case operations of bending the elastic legs inwardly are carried out through the engaging windows of the female buckle over the positions where the engagements between the engaging windows and the engaging projections located in the engaging windows are released.
According to this structure, amounts of deforming the elastic legs by the operations of bending the elastic legs inwardly in order to release the engagements between the engaging windows and the engaging projections can be maintained to be constant by allowing the stopping portions to abut against the elastic legs at predetermined positions of bending the elastic legs. While the elastic legs have rigidities which do not obstruct the bending operations, unexpected deformations or damages are fully prevented for the elastic legs which are caused by excessive deformation operations of the elastic legs.
Also, according to a fourth aspect of the invention, each of the stopping portions in the buckle according to the third aspect of the invention includes a thickness to be stored substantially tightly between the inner walls of the female buckle between which the dividing plate portions extend.
According to this structure, in the engaging condition of the buckles in which the insertion section of the male buckle is inserted into the female buckle, the insertion section can be held inside the female buckle without wobbling, and at the same time, the engaging condition of the buckles can be stably maintained even if the external force in a direction of twisting the insertion section acting around the axis of the female buckle is applied.
Also, according to a fifth aspect of the invention, the stopping portions in the buckle according to the second or fourth aspect of the invention are elongated in the direction of inserting the insertion section of the male buckle.
According to this structure, the stopping portions can be stored substantially tightly between the inner walls of the female buckle in a wide range along the axis of the female buckle, to thereby further prevent the wobbling of the insertion section stored in the female buckle.